This ‘cheat sheet’ is a handy reference, meant for beginning Perl programmers. Not everything is mentioned, but 195 features may already be overwhelming.

Perl 5 cheat sheet v8

 CONTEXTS  SIGILS             ARRAYS        HASHES
 void      $scalar   whole:   @array        %hash
 scalar    @array    slice:   @array[0, 2]  @hash{'a', 'b'}
 list      %hash     element: $array[0]     $hash{'a'}
           &sub
           *glob    SCALAR VALUES
                    number, string, reference, glob, undef
 REFERENCES
 \     references      $$foo[1]       aka $foo->[1]
 $@%&* dereference     $$foo{bar}     aka $foo->{bar}
 []    anon. arrayref  ${$$foo[1]}[2] aka $foo->[1]->[2]
 {}    anon. hashref   ${$$foo[1]}[2] aka $foo->[1][2]
 \()   list of refs
                         NUMBERS vs STRINGS  LINKS
 OPERATOR PRECEDENCE     =          =        perl.plover.com
 ->                      +          .        search.cpan.org
 ++ --                   == !=      eq ne         cpan.org
 **                      < > <= >=  lt gt le ge   pm.org
 ! ~ \ u+ u-             <=>        cmp           tpj.com
 =~ !~                                            perldoc.com
 * / % x                 SYNTAX
 + - .                   for    (LIST) { }, for (a;b;c) { }
 << >>                   while  ( ) { }, until ( ) { }
 named uops              if     ( ) { } elsif ( ) { } else { }
 < > <= >= lt gt le ge   unless ( ) { } elsif ( ) { } else { }
 == != <=> eq ne cmp     for equals foreach (ALWAYS)
 &

 | ^              REGEX METACHARS            REGEX MODIFIERS
 &&               ^     string begin         /i case insens.
 ||               $     str. end (before \n) /m line based ^$
 .. ...           +     one or more          /s . includes \n
 ?:               *     zero or more         /x ign. wh.space
 = += -= *= etc.  ?     zero or one          /g global
 , =>             {3,7} repeat in range
 list ops         ()    capture          REGEX CHARCLASSES
 not              (?:)  no capture       .  == [^\n]
 and              []    character class  \s == [\x20\f\t\r\n]
 or xor           |     alternation      \w == [A-Za-z0-9_]
                  \b    word boundary    \d == [0-9] 
                  \z    string end       \S, \W and \D negate
 DO
 use strict;        DON'T            LINKS
 use warnings;      "$foo"           perl.com       
 my $var;           $$variable_name  perlmonks.org  
 open() or die $!;  `$userinput`     use.perl.org   
 use Modules;       /$userinput/     perl.apache.org
                                     parrotcode.org 
 FUNCTION RETURN LISTS
 stat      localtime    caller         SPECIAL VARIABLES
  0 dev    0 second     0 package      $_    default variable
  1 ino    1 minute     1 filename     $0    program name
  2 mode   2 hour       2 line         $/    input separator
  3 nlink  3 day        3 subroutine   $\    output separator
  4 uid    4 month-1    4 hasargs      $|    autoflush
  5 gid    5 year-1900  5 wantarray    $!    sys/libcall error
  6 rdev   6 weekday    6 evaltext     $@    eval error
  7 size   7 yearday    7 is_require   $$    process ID
  8 atime  8 is_dst     8 hints        $.    line number
  9 mtime               9 bitmask      @ARGV command line args
 10 ctime  just use                    @INC  include paths
 11 blksz  POSIX::      3..9 only      @_    subroutine args
 12 blcks  strftime!    with EXPR      %ENV  environment